In our daily lives, we are unconsciously exposed to surfaces contaminated by microorganisms that may cause diseases. In Korea, these microbial contaminations cause deaths of children and elderly people and lots of people catch diseases caused by various microbes.
Microbial contamination of food is also a global problem. Salmonella, E. coli and other food-derived microbes cause innumerable diseases every year. Acute symptoms include nausea, vomiting, abnormal stomachache, diarrhea, fever and headache. Chronic results may follow the onset of the acute symptoms. Because microbes derived from meat, fish and poultry can be delivered to uncooked food through cross contamination, it will be of great help if the presence of microbes on the kitchen countertop can be detected simply. In addition, in order to ensure the stability of food in food processing industry or to prevent deterioration when producing fermentation products such as beer, it is necessary to quickly detect the presence of microbes.
In general, as methods for detecting pathogenic microorganisms, monitoring of symptoms, observation using a microscope, immunological detection of specific antigens of pathogenic microorganisms, amplification of specific genes through the PCR technology, etc. are used. Although the PCR method allows for very precise and accurate detection, it is greatly affected by several factors because the process of gene amplification is necessary. For the microscopic method to be applicable, the pathogenic organisms should be large enough to be observable with a microscope and should have high density to be easily detectable from a sample. In addition, their morphology should be clearly distinguishable from other organisms.
Therefore, development of a diagnostic sensor capable of detecting microorganisms more accurately and quickly is necessary.